For me (as a programmer) it really varies a ton. I used to put in insane stretches, due to the medication I needed to take in the past and that is how I got used to things in college.
Now I work more regularly, but still can put in a solid 6+ hr day most of the time, and yet some days… yeesh I’m lucky if I can get a third of that. So I work more on other days to compensate.
You mention hours as a programmer?
Is that active coding? Because as you gain experience you may spend less time writing code that will ultimately be replaced by more efficient processes.
E.g. quality over quantity. Are you being more thoughtful during the design process?
This is an “Ask” style community, so the answer is however you feel like it is for your situation - I only got us started to give us a beginning for the conversation:-).
But to answer your question specifically about my own POV: some meetings are very productive, so not “only” the coding, no. Also, the 6 hours is quite the lower bound - it could be twice that if I am on a roll, with programming, with design matters, documentation, or whatever.
You don’t have to overthink it:-). Although you can if you like? :-P